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5.7 Biological Resources

Coast Horned Lizard
The coast horned lizard is a California Species of Special Concern. It occurs throughout much
of California, west of the desert and Cascade-Sierra highlands south to Baja California, Mexico
(Stebbins 2003); however, many of the populations in lowland areas have been reduced or
eliminated due to urbanization and agricultural expansion (Stebbins 2003). It is a small,
spiny, somewhat rounded lizard that occurs in scrubland, grassland, coniferous forest, and
broadleaf woodland vegetation types; it prefers open areas for basking and loose, friable soil
for burrowing. Three factors have contributed to its decline: loss of habitat, overcollecting,
and the introduction of exotic ants. In some places, especially adjacent to urban areas, the
introduced ants have displaced the native species upon which the lizard feeds (Fisher et al.
2002; Suarez and Case 2002; Suarez et al. 2000). In addition to loss of habitat, this species is
also threatened by fires, off-road vehicles, grazing and pets, especially domestic cats
(Jennings and Hayes 1994). In the vicinity of the site, this species has been reported from
Hungry Valley, Tejon Peak, Tehachapi Mountains, and two miles east of Gorman along SR-
138 (CDFW 2015a). This species was observed in several drainages scattered across the
Project site in 2003 (Impact Sciences) and in washes and upland scrub habitat during various
surveys on the Project site in 2015.

Two-Striped Garter Snake

The two-striped garter snake is a California Species of Special Concern. It occurs from
Monterey County, south to Rio Rosario in Baja California, Mexico at elevations between sea
level and approximately 8,000 feet above msl (Stebbins 2003). It is considered locally rare
in southwestern California. The two-striped garter snake is highly aquatic and occurs
primarily in or near perennial or intermittent freshwater streams with rocky beds in riparian
habitats bordered by oak woodlands, willows (Salix spp.), or other dense vegetation
(Jennings and Hayes 1994; Stebbins 2003). The two-striped garter snake feeds on small
fishes, frogs, tadpoles, and earthworms. It is estimated that development and other human
impacts have reduced the historic range of this species in California by 40 percent (Stebbins
2003). A two-striped garter snake was observed in Oso Canyon (Impact Sciences 2003). Due
to the suitable aquatic habitat and the known reported occurrence, it is determined that this
species is expected to occur on the Project site.

Birds

Tricolored Blackbird

The tricolored blackbird is a California Species of Special Concern and a California Candidate
for listing as an Endangered Species. These colonially nesting birds prefer to breed in marsh
vegetation of bulrushes (Schoenoplectus spp.) and cattails (Typha sp.) and have also been
recorded nesting in willows (Salix spp.), blackberries (Rubus spp.), and mustard (Brassica
spp.) (Beedy et al. 1991). During winter months, they are often found foraging in wet
pastures, grasslands, agricultural fields, and seasonal wetlands. Tricolored blackbirds are
nomadic, wandering during the nonbreeding season and occupying colony sites
intermittently (Unitt 1984). There are reported occurrences of this species in the vicinity of
the site along the southern edge of Quail Lake (north of SR-138) and on the shores of Holiday
Lake approximately five miles east of the Project site (CDFW 2015a). The Project site
provides suitable foraging and small amounts of suitable nesting habitat, which consists of

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